Davit



Dec.' 8,1925-, K A. P. scHAT DAvIT Filed Dev. 26, 1919 2 Sheets-Sheet 1 Dec. 8, 1925- 1,564,450 A. P. scHAT DAVIT Filed neg. 26,"1919 2 sheets-sheet 2 In ren/ivf,

(Sch/atp Patented Dec. tl, ltli.

miran ht-tty45@ l? l tl E ANB l?. SCHAT. GF THE HAGUE, NETHERLANDS.

Application filed lecemher 26, 1919. Serial No. 347,638.

To all whom t may concern Be it known that l, Ann l). Scrisse, a citizen of Holland, residing at rlhe fla-gue, in the Province of Zuid, lletlierlands, and Kingdom of the Netherlands, have invented certain new and useful improvements in Davits, of which the following` is a specification.

F or lowering a lifeboat the rope or fall of the boat is often passed around a toggle or a bolla d and then veered hy hand; it is well known, however, that should the mate let the fall slip, a disaster is practically inevitable. Another method of lowering` a boat consists in that the fall runs directly from the davit to a fall drum provided with a band-brake. but a band-brake has the unfortunate feature that the presence of water or oil between the band and the brake disc may cause the heavy boat to plump down notwithstanding` the utmost efforts of the lorakeman.

rllhe object of my present invention is to provide improved means by which the lowering of heavy loads such as lifehoats may be effected with greater safety than heretofore. With this main object in view the rope or fall is secured to the drum of a hoisting apparatus and between the load and said drum passed over one or a plurality of friction surfaces which during the unwinding operation are, or may be, prevented from turningv in the direction. of the rope. lt will be understood that with these means the tension of the rope or fall is almost entirely taken up by said friction surfaces, whereby the hoisting` apparatus is released from any considerable strain during;` the lowering operation.

ln case the hoisting` apparatus is actuated by a worm meshing with a worm wheel on the fall-drum, 'said worin is preferably inado to act selfbrahingr. Vlith such a self-brakiniy worin the mato may safely release the handle during the lowering` operation without tho load falling. Ewing to the fact that during the lowering of the boat, the fall-drum, and consequently also the self-braking worm, have to take up only an insignificant part of the load, my invention allows of the provision of means whereby the shaft of the worm is driven with increased rotary speed from a suitable driving,` shaft so that loweringl may be effected very quickly. The said fact also permits of making the worin nonself-braking and of providing' the shaft of the worin with an ordinary band brake or the like for controlling' the loweringI speed, as a very small braking; power herevsufi/ices for instantly stopping the descending1 lioat.

lt should be noticed that both. falls of the one boat mav be wound on one and the same drum whe inequality between the lowerino' speeds of said falls is obviated; the saure effect may be realized by winding the said falls on individual drums actuated by com mon driving` means.

The friction surfaces between the boat and the hoisting apparatus are preferably made so as to have freedom of rotation in the direction of motion of the fall during` the hoisting operation but to remain stationary when the rope passing over the suine is unwound. lf desired. however, these friction surfaces may be allowet to follow the movement of the rope during the lowering operation.

ln the annexed drawing, Fig. l illustrates a front elevational view of a lifeboat, and Fig. 2 a plan view of part of said boat which, in both cases, is coupletl with my improvements.

The boat l is suspended from a davit 3 by means of a rope or fall 2. Said rope is associated with the drum i of a winch, and inter'- mediate between said druni and the davit 3 passed around a bollard 5 which here constitutes the friction surface mentioned here-- inbefore. rThe said bollard has freedom of rotary motion in the direct-ion of the arrow shown, but a suitable ratchet mechanism 5 prevents it from turniing` in the reverse direcv tion. llt will be Vreadily understood that the bollard 5 does not offer ..iy noticeable resistance against the winding, of the rope, but that it takes up av considerable part of the strain during the lowering operation, when it is held stationary hy the ratchet gear 5a.

Secured to the drinn is a worin wheel meshing with worin bodiment illustrated, is of the selfnalring type. Keyed to the spindle 8 of theworm is a gear 9, and also a pinion l0 which, 1n the position shown in l? l, meshes with a gear Wheel ll. The said gear ll is secured on a sleeve 13 which carries a pinion l2, and which is slidably hut non-rotatably mounted on a shaft 14. rEhe .pinion l2 meshes with a gear l5 on a shaft 1G which as well as shaft lll, is provided with a square end for receiving a suitable operating handle.

rlhe arrangement is such that an axial displacement of the sleeve 13 through a certain which, in the em-A distance causes the pinion to mesh .with gear 9 and the pinion iOto disengage the gear ll.

When it is required for the boat to be lowered, the sleeve i3 is moved into the position shown in Fig. and the operating handle placed on shaft 16. If now the handle is turned the speed of shaft 14ris geared up, whereby the worm 7 rotates at increased speed and the lfall is unwound Very quickly. By placing the handle on the intermediate shaft lf!- the gearing up may beA reduced.

For hoisting the boat the pinion l2 is brought into position to mesh with gear. 9, and the oi'ierating handle put on shaft le, whereby the rotary speed of the driving shaft is geared down liefore being transmitted to the worm T. If the falls are unloaded the. speed of the driving shaft may be geared up also during the lowering operation. Y

The da 'its shown in the drawings are inclined toward the water to cause them. to swing outboard automatically, as is the case with the davits Shown in my pending applications, rescates, :riesen-ie, assegno, and. #347,637; but it will be undfn'stood that the device works well with any automatic davit, and also with non-automatic davits. the former it controls the rotary move-ment ofthe davit in both directions-inboard and outboard-wl'iile with the latter it is good frr hauling in the boat.

But attention is called to the fact that my device is specially useful with automatic davits, because of the. speciai cliiiiculty experienced with this class' of davits in controlling their rotary outboard movement under the greatly varying conditions of load, etc., which movement is in a substantially horizontal direction, and therefore calculated to subject the davit and operating mechanism connected therewith to objectionable lateral strains, and is often an occasion of danger to passengers in the boat.

Of all automatic dar/its, the inclined davits are hardest to control in their rotary outboard movement, because the rocking and listing of the ship causes great variations in the inclination of the davit, and correspondingly great variations in its rotatable tendency under dili'ferent conditions.

It will be seen that my arrangement .gives such a light strain on the operating mechanism connected with the drum, that fully loaded boat can be easily set overboard with great evenness and regularity of movement, in a manner altogether satisfactory.

Having now described my invention, what I claim as newand desire to protect by Letters Patent is 1. In a device of the character described, a ydavit having a rope; a boat connected to the outer end thereof; a drum for the hauling end of the rope; and a member supported on the deck of the ship at a point in the path of the rope bet veen the davit and the drum, said member having a friction surface with the hauling part of the rope passe-d around said surface and held in frictional engagement therewith by the tension in the rope, said member having freedom of rotation in the direction of the travel of the rope when the rope is wound upon the drum, andy having means for locking it against-:rotation in the opposite direction; whereby to automatically introduce fri-ctional resistanceV in the part of the rope bctween the davit.y and the ,drum during the outward movement of the rope from thedrum, and te` permit the free movement of the rope asit is wound upon the drum.

2. In a device of the character described, alifeboat; a 'davit rotatable on its longitudinal anis to inboard andl outboard'position, andv having a rope for engaging the lifeboat; a drum ,for tl eA hauling end of the rope; `and a member'supported,on the deck of the-ship. at a point in the rope betweenthc davit andtheA drum, and having a friction surface with the hauling part of the rope passed around Y said surface and held in frictional engagement therewith by the tension'in the rope, said member having` freedomof rotation in theV direction of travel of the rope when the rope is wound upon the drumto raise the boat and swing the davit inboardand having means for locking it against rotation in the opposite direction.

3. Ina device of the character described, a lifeboat-.and a davit for handling the boat, said davitbeingmovable to inboard and outboard position, and having a rope connected at itsouter end to the boat; a drum lat the inner end of the rope for hauling in and paying out the rope, to cont-rol the movements of the davit and the boat; and means automatically operable for reducing the strain of the load on the drum as the rope is paid out thereby.

4. In a device of the character described, a ,davitmovable to inboard and outboard position and biased to swingoutboard; a rope forY the davit; a boat connected to the outerend of the rope; a self-braking drum at the, inner end of the rope for hauling in and payingout the rope to control the movements of the davit and of the boat; and means automatically operable for reducing the strain of the load on the drum proportionate to the weight of the load, as the rope is. paid out `by the drum.

In testimony whereof I a-iiix ymy signature.

ANE P. SCI-IAT. 

